A networking switch device receives frames through a number of ingress ports connected to the switch device and forwards the frames through a number of egress ports connected to the switch device. The switch device determines one or more egress ports through which the received frames are forwarded dependent on the destination address included in the frame.
A logical link can be configured to increase the bandwidth to a destination; that is, the number of frames that can be forwarded through the switch device. A logical link includes a plurality of egress ports in the switch through which frames can be forwarded to the destination. Configuring multiple ports to forward frames to a destination is called link aggregation or trunking. The egress ports in the logical link are configured as members of the logical link or the trunk group.
A multistage switch includes a plurality of coupled switch devices. One well-known method for providing a multistage switch is the 3-stage Clos network. The multistage switch includes external ports for receiving frames from a source and forwarding frames to a destination. Each switch device in the multistage switch (or matrix) includes internal ports for forwarding frames within the matrix.
Typically, a frame received from a source at one external port is forwarded through the switch devices in the multistage switch to another external port dependent on a destination address associated with the frame. A switch device in the matrix forwards a received frame to one of its output ports dependent on a destination address included in the frame. The destination address may be for a host such as a computer, another multistage switch or a router.